Ments



(No Model.)

N. A. CHATPIBLD. PROCESS OP AND APPARATUS POR PNBUMATIG DRAWING.

TN: Noam rusas po., mufo-'mno., wAsmNman, n. c.

UNITED STATES PATENT OFFICE.

NORMAN A. vCHATFIELD, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN-MENTS, OF ONE-HALF TO ABSALOINI E. HOOVER, OF SAME PLACE.

PROCESS lOF AND APPARATUS FOR PNEUMATIC DRAWING.

SPECIFICATION forming part of Letters Patent No. 461,667, dated October20, 1.891.

Application led November 29, 1890. Serial No. 373.095. (No model.)

To all whom it may concern:

Be it known that I, NORMAN A. CHATFIELD, a citizen of the United States,residing at Chicago, Cook county, Illinois, have invented a new anduseful Process of Pneumatic Drawing and Apparatus for Carrying out SuchProcess, of which the following is a specification.

I have discovered by continued experiment 1o that if crayon, dry paint,black-lead, or other coloring-matter or similar substance bepneumatically forced while in a powdered or finelydivided state againstthe surface of the paper or other material used in drawing the particles of the substance will become attached thereto or be forced underor between the ibers of the paper, or, in other words, become partiallyincorporated therewith, producing a mark of greater or less sizeaccording` to the size of the current of compressed air, or according asthe apparatus is moved toward or from the paper. By moving the apparatusthrough which the current passes in one direction or another, lines ofany form or dimensions may be formed.

This process may be employed in drawing and finishing portraits,landscapes, designs, dac., and to carry out suchl process I have deviseda machine whereby the current of compressed air may be directed asdesired, and whereby the crayon or other substance used may be powderedor ground and introduced into the current of air; and my inventionconsists in the process and apparatus for carrying out the same, ashereinafter described.

In the drawings, Figure l is `a central vertical longitudinal section ofthe pneumatic pencil used in carrying out the process; Fig. 2, a similarsection of the grinding-machine; Fig. 3, a section on line 3 3 of Fig.2, looking in the direction of the arrow; Fig. 4, a perspective view ofa cradle or frame used to support the substance being ground, and Fig. 5similar views of parts of the apparatus.

The pencil A is made of any suitable dimensions, and, as shown, ishollow throughout its length and provided with a tip a, adjustablyconnected to the body of the pencil by screw-threads or in any othersuitable manner. The size of the opening in this tip delble tube, whichis connected, as hereinafter described, with the grinding-machine. Thisgrinding-machine consists of a case or sheathl 6o made in two parts BB', the part B consisting of a case or sheath of suitable dimensions toreceive the partsv hereinafter to be described, and made of any suitablematerial .and preferably in the form shown in Figs. 2 65 and 3 of thedrawings, and provided with clampsI, whereby it is attached totheordinary man1-stick. The part B consists of a tube attached by means ofscrew-threads or in any other suitable manner to the case B', 7o Y asshown. To the left-hand end of this tube B is attached a taper thimbleb, adapted to be connected with any suitable source of compressed airand supply-as, for instance, an air pump or reservoir. A similar thimbleb is attached to the right-hand end of the sheath B and is connected,preferably by means of a flexible tube, (not shown,) with the rear endofthe tube A. To prevent clogging of the tube, I prefer to place overthe inner end of 8o the thimble b a piece of wire-gauze b. In the tube Bis secured a frame or cradle C, preferably made in the form shown inFig. 4, wherein it is circular at one end and semicircular at the other,of a proper size to fit the interior of the tube, the two end piecesbeing connected by side bars or rods. kThe circular end is open, asshown, to afford a free passage for the air. .This cradle is providedwithcrossbarsc, on which is placed the material to be 9o ground, and aset-screw c', whereby the sides of thecradle are adj usted to bindagainst such material and hold it in place. The cradle when insertedinto lthe tube B may be held in place by means of the end of the sheathB and the taper thimble Z), though any other means may be used, asdesired. Immediately above the cradle is placed a bow D, preferably ofthe form shown more particularly in Fig. 5, and a piece of emery-clothor similar roo substance E is attached to the downwardlyprojecting endsof the bow D by means of clamp-plates d d', which are screwed to the endof the bow. A loop F is attached to the forward end of the bow, and tothis is fastened one end of an elastic band G, the other end of which isattached to a cross-rod g, engaging with notches in the rearward side ofthe circular end of the cradle C, by means whereof the elastic band andbow may be adjusted at different distances from the cradle C. Theclamp-plate CZ is provided with a loop, as shown, through which theelastic band passes, and which serves as a guide for such band andsupport for the bow. I next construct a segmental lever H, which ispivoted in the sheath B. To one end of this lever is attached a strap h,the other end of which is attached to a loop in the clamp-plate d. Theshaft cr spindle of the lever H passes, as shown in Fig. 3, out throughthe case, and a lever H is secured thereto, the opening where the shaftpasses through the case being covered by an elastic tube h to preventthe escape of air. From this construction it will be seen that as thelever II is pressed toward the right, Fig. 2, the lever I-I will bemoved in the same direction, carrying along with it the bow and theemery-cloth attached thereto, drawing such cloth across the surface ofthe material to be ground and'grinding a portion thereof, and that asthe pressnre on the lever H is released the elastic band G will draw thebow and paper toward the left, Fig. 2, bringing the lever II into theposition shown in the dotted lines and again drawing the emery-clothacross the su rface of the material to be ground. In this way byalternately pressing the lever H and releasing such pressure areciprocating motion is imparted to the bow and cloth, which pass backand forth upon the surface of the material, grinding otf particles fromthe same.

The parts being constructed and put together as shown, the thimble bbeing connected with a suitable source of compressed air, and thethimble ZJ with the pneumatic pencil, the device is operated as follows:The case inclosing the grinding mechanism is preferably held in the lefthand and the pneumatic pencil in the right. The air is admitted underpressure to the case B B', and a reciprocating motion being imparted tothe bow and emery-cloth, as hereinbefore described, the materialsupported in the cradle is ground with greater or less rapidity, asdesired. As the particles are ground off they immediately enter theblast, which becomes charged therewith and by which they are carriedthrough the pencil and forced against the paper to which they attachthemselves or with which they become partially incorporated. By movingthe pencil as necessary any portrait, landscape, design, the., may bedrawn upon the paper or other material used. By varying the intensity ofthe blast the size of the nozzle a and the rapidity of the grinding theintensity and size of the line drawn may be varied easily, as occasionmay demand.

In using this apparatus lines of the utmost fineness and delicacy maybedrawn, and drawings ofanysort and inanycolorcan be executed with greatrapidity and precision. As great force is exerted by the blast, thefinely-divided particles are not only deposited upon the surface of thematerial used, but, as shown by a microscopical examination, they areforced between or partially under the bers thereof, becoming to agreater or less extent incorporated with a part of the material itself.This adds greatly to the durability of the drawings, the lines, if madeby a current or stream of air under pressure, being almost indelible.

As will be evident, the apparatusis exceedingly simple, consisting, asit does, of but few parts, which are easily adjusted or replaced. Itshould be understood that I do not intend to limit myself to the exactforms herein given to the several parts, since form not being essentialto the successful operation of the device the parts may be varied inmany ways, as desired-as, for example, a coiled spring may be used inplace of the elastic band G, or the tube may be attached to the ypencilin other ways than that herein shown,

and any such changes I regard as coming within the spirit and gist of myinvention, which consists, as regards the process in drawing pictures,dac., by pneumatically forcing powdered or finely-divided materialagainst the surface upon which the picture is to be drawn and as regardsthe apparatus in providing a suitable device for carrying out theprocess. i

In order to carry out the process, it is not necessary to use the exactform of mechanism herein shown, since the material may be governed inany other way desired and then forced against the surface on which thedrawing is to be made by the air-pressure. The machine herein shown istherefore intended but as an illustration of one form of apparatus bymeans whereof the process may be carried out, and as a limitation tothat form alone.

I claiml. The process of drawing, which consists in pneu maticallyforcing finely-divided crayon, dry paint, or similar material against adry surface upon which the drawing is to be made, whereby the particlesof such material become attached to such surface, substantially asdescribed.

2. The process of drawing, which consists in reducing crayon, dry paint,or similar material to a finely-divided state while exposed to anair-blast,'whereby as the particles of such material are ground olf theyare carried along by the blast and forced against the su rface uponwhich the drawing is to be made, becoming thereby incorporated with suchsu rface, substantially as described.

3. The combination of a hollow pencil, a

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grinding mechanism connected therewith, and means for forcing airthrough the pencil and grinding mechanism, whereby the substance groundis blown out through the pencil, substantially as described.

4. The combination of a case B B, a cradle C, a bow D, grinding materialsecured by means of suitable clamps, and means for imparting areciprocating motion to such bow, substantially as described.

5. The combination of a case B B', a cradle C, a grinding-bow D, an4elastic band G, attached to the bow and cradle, a lever H, connected tothe bow, a lever H', rigidly attached to the lever H, whereby the bow ismoved in one direction by the lever H and in the other by means of theband G when the lever is released, substantially as described.

6. 'A cradle C, provided with cross-bars cto support the material to beground, and a setscrew c', substantially as described.

7. The combination of a case B B, acradle C, a bow D, grinding materialsecured thereto. a lever H and band G, attached to the bow, a lever H',rigidly connected to the lever H, a pencil A, connected to the case BB', and means for forcing air. through thecase and pencil, wherebyT` asthe material upon the cradle is ground by means of the bow it is blownby the air through the pencil, substantially as described.

S. The combination ot' a cradle, a grindingbow, and an elastic bandattached to the bow and adjustably connected with the cradle, wherebythe bow is adj usted at different distances from the cradle,substantially as described..

NORMAN A. CHATFIELD.

Witnesses:

THOMAS A. BANNING, SAMUEL E. HIBBEN.

